1. Field of the Invention
The present invention relates generally to merchandising machines, and in particular to multipurpose, refrigerated food merchandising machines of the type having a rotatable carousel which is divided into compartments for receiving merchandise to be vended from the machine. Even more particularly, the present invention relates to a control system for controlling the rotation of the carousel within such a machine.
2. Description of the Related Art
Multipurpose, refrigerated merchandising machines of the type which include a rotatable carousel divided into compartments for receiving merchandise to be vended from the machine are well-known in the art. Examples of such machines are disclosed in U.S. Pat. Nos. 4,317,604, 4,391,388, and 4,927,051. Such machines include a generally rectangular cabinet having a front door which can be opened by an operator to service and stock the machine. The front door includes a viewing area for viewing products disposed in the machine. The viewing area may comprise a plurality of transparent windows and a plurality of movable, transparent delivery doors which a customer can open to retrieve a product once sufficient money has been inserted.
These known merchandising machines include a drive mechanism for rotating the carousel, and a refrigeration system for recycling chilled air through the cabinet. These machines also include a microprocessor for controlling and tracking, among other things, movement of the carousel. For instance, in the U.S. Pat. No. '051 there is described a control logic which records and stores information relating to the number of full or empty compartments within the carousel. A predetermined time after a vend, i.e., a purchase by a customer, has occurred from the machine, the carousel is automatically rotated upon instruction from the microprocessor to place that portion of the carousel which contains the greatest number of full compartments in the vicinity immediately adjacent the viewing area. While the purpose of such a control system appears to be an attempt to induce sales from the vending machine by displaying the maximum amount of product possible in the viewing area, such a logic may not accomplish that purpose since it will, in at least some instances, place the least desirable products disposed within the machine in the viewing area, thereby discouraging sales.
Merchandising machines of the type to which the present invention is directed are subject to environmental regulations of local authorities to insure that food vended from the machine remains fresh. Typically, such regulations require that the interior of the cabinet be maintained at about 40.degree. F. However, the refrigeration system in such known carousel-type merchandising machines, since it is based on a forced air distribution system, results in temperature gradients throughout the cabinet. These temperature gradients are created by obstructions to the air flow the position of delivery and air return registers, variances in insulation thickness and efficiency, etc. Thus, certain portions of the interior of the cabinet are warmer than other portions.
Typically, the warmer areas of the cabinet interior are those closest to the viewing area since light fixtures, designed to illuminate the product, warm that portion of the cabinet next to the viewing area. Moreover, when a customer opens a delivery door to retrieve a product, cold air escapes and the warmer ambient air enters the cabinet. In such instances, the dispensable products in those compartments adjacent the viewing area are subjected to warmer temperatures and may spoil before their expiration date.
The merchandiser described in the above-referenced U.S. Pat. No. '051 amplifies this problem since the fullest section of the carousel is usually positioned adjacent the viewing area and remains in that position until additional vends are made from the machine. This causes a significant number of products in the machine to be subjected to higher temperatures for a long enough time to create spoilage. The products stored in the rear section of the machine, on the other hand, may freeze because they are subjected to a continuous flow of refrigerated air unmoderated by the warming influence of the viewing area.
Other known control systems for rotating the carousel of the above-described type of merchandising machine have been programmed to rotate the carousel one full revolution every fixed time interval, such as three minutes, to thereby parade all of the products past the viewing are in the hopes of encouraging impulse sales of those products. However, periodically rotating the carousel one complete revolution does not solve the problem since the carousel is always returned to its original position.
One object of the present invention is to provide an improved control system for a multipurpose, refrigerated merchandising machine.
Another object of the invention is to provide an improved control system for a multipurpose, refrigerated merchandising machine which attracts customers even as the supply of articles in the machine is depleted.
Another object of the present invention is to provide, through periodic rotation of the carousel, improved air circulation and temperature distribution within the cabinet to thereby maintain the products disposed in the machine at the average cabinet temperature.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.